Users often submit keyword-based queries to search engines in search of desired information. In response to receiving such queries, search engines identify those documents determined to most closely satisfy the query, rank the identified documents based upon keyword-based relevance and present a ranked listing of documents to the user. Those documents of higher ranking are determined to be more relevant and thus receive more prominent placement (e.g., at or toward the top of a vertical listing). While search engines strive to return the most relevant and desired results, there is any number of reasons why the documents returned may be unsatisfactory to the user. One such reason is that a subject of an input search query may have various versions and the results returned, while satisfying the keyword-based subject of the query, may fail to provide information about the desired version.
Many entities (or query subjects) have multiple versions and versions can differ based upon the nature of the entity. For instance, many car models are released every year and each year's model may be viewed as a different version (e.g., HONDA ACCORD 2010 and HONDA ACCORD 2011). Similarly, many events occur at regular intervals and each interval may be viewed as a different version (e.g., NBA Playoffs 2009 and NBA Playoffs 2010). Additionally, some products, for instance software products, use different numerical designations to indicate different versions (e.g., INTERNET EXPLORER 8 and INTERNET EXPLORER 9). There are also queries which, while having a specific version denoted, do so in a relative rather than a fixed manner. For instance, a query may indicate “events in Seattle tomorrow.” “Tomorrow” is the particular version designated but the value of the designation changes with time and results relevant today will differ from those relevant based on the same query tomorrow.
Query subjects having multiple versions can lead to unsatisfactory search results. For instance, users often input only the subject of the versions (e.g., “HONDA ACCORD”) without an accompanying indication for which version they would like to see results. Additionally, even if the user enters a version-intent (that is, a designation of a particular version within the search query itself), the version may be only one of multiple keywords upon which results are ranked and, as such, results closely matching other portions of the query may appear more prominently, or instead of, results that include information about the desired version.